There are many types and forms of tools used to assist a craftsman with the job of measuring and marking of angles while working on a project. Perhaps the most well known tool for roofing carpenters is the speed square invented in 1925 and sold by the Swanson Tool Company. The speed square comprises a right-angle (90 degree) triangle generally made from metal or plastic and includes markings on the hypotenuse corresponding to degrees as well as markings corresponding to unit rise over run values traditionally used to measure the angles on a roof. A craftsman, such as a roofing carpenter, may use this tool to mark the proper base cut of a rafter corresponding to the rise and run of the roof being constructed.
Despite its wide spread use, there are many disadvantages to the speed square and similar tools known in the art. First, the design of the speed square requires the use of two hands with one hand holding one corner of the device and pivoting the unit with the other hand to measure or mark angles onto a work piece. Second, the device does not provide a means to lock a desired angle in place and therefore it requires a great deal of wasted time to mark multiple identical angles onto a work piece. Third, the traditional speed square is limited in its functionality by not providing a means to measure levels on different planes (e.g. measure horizontal and vertical levels). Fourth, the traditional speed square is also not able to measure angles between two points at a distance (i.e. from the top to the bottom of a stairway). Finally, it is not able to act as a compass to mark circular lines of specific sizes onto a work piece or drawing.
There is therefore a great need in the field for a new multi-use hand tool which is compact and can be easily carried by a craftsman on a job site and that is able to measure and mark angles, lock the device at desired angle to easily mark multiple lines at that desired angle, measure levels in multiple planes, measure angles between two points at a distance, and draw circular lines of specific and various sizes.